When should I use the negative milestone unlocks?

The most recent timed event zone of Adventure Capitalist, "New You", has a set of paired investments, a healthy and slow option and a corresponding unhealthy and fast. Every other milestone unlock for the unhealthy option sabotages the speed of the already slow healthy option.

Currently I'm just buying 25 of the unhealthy investments to get to the first unlock (which boosts the unhealthy investment without sabotaging the healthy) and open up some of the "X of everything" unlocks, then focusing entirely on the healthy investments. I'm not sure if this is the optimal strategy to unlock everything before the timed event expires, but I am nervous about too much sabotage to the healthy investments.

When should I purchase the unhealthy investments so that I can unlock all of the badges, megabucks and gold milestones without crippling the income from my healthy investments?